This invention relates to a cellular molded article in a mold pattern having a surface skin, which is used for such as the interior trim material of an automobile, and a producing method thereof.
As a conventional producing method of a cellular molded article having a surface skin in this kind, it is known as a so-called simultaneous unification molding to one piece that, for example, on either one of two metal molds by which a mold pattern is formed, a surface skin material of thermoplastic resin is arranged, and after clamping the metal molds, pre-expanded beads are fed into this mold pattern, then the pre-expanded beads are expanded and melt united each other by steam heating, and at the same time, these pre-expanded beads and the above mentioned surface skin material of thermoplastic resin are melt united together to one piece.
In this simultaneous unification molding to one piece, in each inside of the above mentioned two metal molds, a chamber connected with a steam valve, a decompression valve and such others are provided. And, on the one metal mold to which the above mentioned surface skin material will be arranged, a plural number of decompression holes which connect with the above mentioned chamber are provided, at the same time, on the other metal mold, a plural number of decompression holes which connect with the above mentioned chamber are provided. And, at a time of the above mentioned expansion molding, by means of supplying steam into the mold pattern from the steam holes on the above mentioned other metal mold, the filled pre-expanded beads in this mold pattern are heat expanded.
In this step, in order to make an effective expansion molding by pre-heating the above mentioned surface skin material, before arranging this surface skin material, by means of supplying steam into the above mentioned chamber, the above mentioned other metal mold is often pre-heated.
However, in a case of preheating the above mentioned one metal mold as in the above, if an olefin thermoplastic resin elastomer is employed as the above mentioned surface skin material, after molding it, at a time of mold releasing of the cellular molded article in the mold pattern having the surface skin from the above mentioned one metal mold, the above mentioned surface skin material will stick on the above mentioned one metal mold, and therefore it will often cause a hard release from the above mentioned one metal mold.
Usually, before releasing it, it is cooled down by water or the like, but it will not be sufficient. While, a long time cooling is not preferable due to a longer producing cycle.
At a time of releasing the cellular molded article in the mold pattern having the surface skin after the end of molding, if the above mentioned surface skin material sticks on the metal mold as in the above, an automatic releasing of the molded article from the molding machine becomes hard, subsequently, it will raise its production cost by a longer time of molding cycle, or by addition of equipment, tools or the like for releasing the molded article from the molding machine. Furthermore, as releasing the stuck molded article by force from the face of metal mold, there is a problem that design of the surface skin will be deteriorated.
This invention is to solve the above mentioned problems, and even in a case of preheating the above mentioned one metal mold, sticking the surface skin material on the above mentioned one metal mold will practically not be appeared, and therefore, it is an object to provide a producing method of the cellular molded article in the mold pattern having the surface skin and a molded article thereby, which are free from problems of the molding operation.
To achieve the above mentioned object, an essential feature residing in the invention which is claimed is that, a measure for producing method of the cellular molded article in the mold pattern having a surface skin is that, a producing method which is, after thermoforming of a surface skin material along by a metal mold face of either one of two metal molds which compose a mold pattern, by means of expansion molding in this mold pattern, the above mentioned surface skin material is melt united to one piece with a surface of cellular molded article in the mold pattern to be molded, and at least a face of the above mentioned surface skin material, which contacts with a metal mold, is an olefin thermoplastic elastomer sheet which is composed of an olefin resin without containing a polyethylene resin as its matrix, and pre-expanded beads, which are employed for an expansion molding in the mold pattern, are pre-expanded beads of an olefin resin.
An essential feature residing the invention which is claimed is that, a measure that at least a face of the above mentioned surface skin material contacting with a metal mold is composed of a domain, which contains a polyethylene resin as its composing raw material resin and is formed by dynamic curing, and an olefin thermoplastic elastomer sheet which is composed of an olefin resin without containing a polyethylene resin as a matrix, and pre-expanded beads to be employed for an expansion molding in the mold pattern are pre-expanded beads of an olefin resin.
An essential feature residing in the invention which is claimed is that, a measure is that the above mentioned olefin pre-expanded beads are pre-expanded beads of a propylene resin.
An essential feature residing in the invention which is claimed is that, a measure is that the above mentioned olefin pre-expanded beads are pre-expanded beads of a polyethylene resin.
An essential feature residing in the invention which is claimed is that, a measure is that the above mentioned olefin resin as a matrix is a polypropylene resin.
An essential feature residing in the invention which is claimed is that, a measure is that the above mentioned polyethylene resin which is not included as a matrix is a linear low density polyethylene resin.
An essential feature residing in the invention which is claimed is that, a measure is that at least the one metal mold is composed of an aluminum metal.
An essential feature residing in the invention which is claimed is that on the surface of the above mentioned one metal mold, a design pattern, which will be printed on a sheet at a time of thermal forming of the sheet, is attached.
An essential feature residing in the invention which is claimed is that, a measure for the cellular molded article in the mold pattern having the surface skin which is prepared by that, after thermo-forming of a surface skin material along by either one of metal mold face of two metal molds which compose a mold pattern, by means of expansion molding in this mold pattern, the above mentioned surface skin material is melt united to one piece with a surface of cellular molded article to be molded, and at least one face of the above mentioned surface skin material which contacts with a metal mold is composed of an olefin thermoplastic elastomer sheet which is composed of an olefin resin without containing a polyethylene resin as a matrix, and pre-expanded beads which will be employed for an expansion molding in the mold pattern are pre-expanded beads of an olefin resin.
An essential feature residing in the invention which is claimed is that, a measure for the cellular molded article in the mold pattern having the surface skin is that, at least one face of the above mentioned surface skin material which contacts with a metal mold is an olefin thermoplastic elastomer sheet composed of an olefin resin without containing a polyethylene resin, and pre-expanded beads, which will be employed for an expansion molding in the mold pattern, are pre-expanded beads of an olefin resin.
An essential feature residing in the invention which is claimed is that, a measure for the interior trim material of ion automobile comprises the cellular molded article in the mold pattern having the surface skin which is claimed.
An essential feature residing in the invention which is claimed is that, a measure for the cellular molded article in the mold pattern having the surface skin is that pre-expanded beads of the above mentioned olefin resin are pre-expanded beads of a polypropylene resin.
An essential feature residing in the invention which is claimed is that, a measure for the cellular molded article in the mold pattern having the surface skin is that pre-expanded beads of the above mentioned olefin resin are pre-expanded beads of a polyethylene resin.
An essential feature residing in the invention which is claimed is that, a measure for the cellular molded article in the mold pattern having the surface skin is that the above mentioned olefin resin as a matrix is a polypropylene resin.
An essential feature residing in the invention which is claimed is that, a measure for the cellular molded article in the mold pattern having the surface skin is that the above mentioned polyethylene resin which is not included as a matrix is a ar low density polyethylene resin.